QuakeIndex

Fault · California

Garlock fault

257 kmlong (160 mi), as mapped
> 5 mm/yrhow fast it slips
last 150 yearssince it last broke the surface
267quakes of M2.5+ within 10 km since 2016

In plain English

The two sides grind past each other faster than 5 mm a year — more than half a metre (20 inches) every century.

It has broken the ground surface within the last 150 years.

The largest earthquake recorded near it was M 7.5 in 1952 (The 1952 Kern County, California Earthquake) — about 5,600,000 times the energy of an M3.0, the size people start to feel. It released about 2.7 megatons of TNT.

USGS maps it as 3 sections: Central Garlock section, Eastern Garlock section, Western Garlock section.

This week vs. its last ten years

54/100

typical

1 quake of M1.5+ within 5 km of the trace in the last 7 days — busier than 54% of weeks since 2016. A normal week: 0–1.

Computed from the USGS catalogue · a description of the past, not a forecast · method

San Andreas faultSouthern Sierra Nevada faultSanta Ynez faultLenwood-Lockhart faultHelendale-South Lockhart faultKern Canyon faultSan Gabriel faultCalico-Hidalgo faultPanamint Valley faultPisgah-Bullion faultCamp Rock-Emerson-Copper Mountain faultMission Ridge fault systemSan Juan faultHarper faultBlackwater faultAsh Hill faultJohnson Valley faultSouthern Death Valley faultLittle Lake faultWhite Wolf faultLavic Lake faultPleito faultBullion Mountains faultManix faultAirport Lake faultWheeler Ridge faultLos Alamos faultOwl Lake faultEdison faultMt. General faultRed Pass faultTank Canyon faultBreckenridge faultKern Front faultNew Hope fault M 7.5 · 1952 · The 1952 Kern County, California Earthquake
The Garlock fault as mapped at the surface (glowing), with the other mapped faults nearby, 267 of the M2.5+ earthquakes within 10 km of it since 2016 (dots), and the epicentres of the large historic earthquakes recorded near it (rings). Traces: USGS Quaternary Fault and Fold Database. Historic epicentres are estimates.

Every year since 2016

Earthquakes of M2.5+ with an epicentre within 10 km of the mapped trace. Near is not the same as on: some will have slipped on neighbouring faults.

The big ones recorded near it

  1. M 7.5 The 1952 Kern County, California Earthquake
    July 21, 1952 · epicentre 16 km from the trace
  2. M 4.5 23km S of Trona, CA
    July 6, 2019 · epicentre 4 km from the trace
  3. M 4.3 18 km WSW of Johannesburg, CA
    July 13, 2026 · epicentre 8 km from the trace
  4. M 4.3 20km S of Trona, CA
    July 6, 2019 · epicentre 7 km from the trace
  5. M 4.1 2 km ESE of Frazier Park, CA
    July 12, 2026 · epicentre on the trace
  6. M 4.1 18 km WSW of Johannesburg, CA
    June 1, 2026 · epicentre 8 km from the trace
  7. M 4.0 21km S of Trona, CA
    July 6, 2019 · epicentre 6 km from the trace

Before 1973 from the USGS ComCat historical catalogue (within 25 km; epicentres of old earthquakes are estimates). Since 2016, M4+ within 10 km.

Most recent near it

  1. M 2.6 17 km WSW of Johannesburg, CA
    2026-09-24 · 8 km from the trace
  2. M 3.0 17 km WSW of Johannesburg, CA
    2026-09-23 · 8 km from the trace
  3. M 3.2 17 km WSW of Johannesburg, CA
    2026-09-23 · 8 km from the trace
  4. M 2.5 17 km WSW of Johannesburg, CA
    2026-09-23 · 9 km from the trace
  5. M 2.8 16 km WSW of Johannesburg, CA
    2026-09-08 · 7 km from the trace
  6. M 2.8 18 km WSW of Johannesburg, CA
    2026-07-14 · 7 km from the trace

Neighbouring faults

Fault trace, slip rate and age: USGS Quaternary Fault and Fold Database (public domain), simplified for the web. Earthquakes: USGS ComCat. QuakeIndex does not forecast earthquakes; a fault's history describes the past. For early warning use ShakeAlert.